This invention relates to systems or devices that treat an exhaust gas or other gas stream by introducing one or more additives into the gas stream and for mixers used in such systems to mix the additive with the exhaust gas, often upstream of a catalyst.
It is known to treat exhaust gases or other gas streams by introducing one or more additives into the exhaust gas in order to enhance or create a catalytic reaction in a device downstream from the injection for the purpose of reducing undesirable emissions. In one known system, a reducing agent is injected into the exhaust gas of a diesel engine in order to reduce the amount of nitrogen oxides (NOx) in the exhaust gas via catalytic reduction. In such systems, it is known for the additive to be provided in the form of ammonia or urea (dissolved in water) prior to the catalytic reaction. When this is done, it is important to obtain adequate mixing of the exhaust gas with the additive/reducing agent.